Filter



July 6 1926. J

. E. 1.. OLIVER ET AL FILTER Filed Nov. 5, 1921 3 Sheets-Sheet 1 lu-auuimuwnmii n 1 ml =qml q= M v Q m i H E 0 M23 H E H v H b MN NW MN R Q 0 6 ,\.N NM 1 0 3w W O N hm N nN Ffiarih July 6 1926.

E. OLIVER ET AL FILTER 3 Sheets-Sheet 2 Filed Nov. 5, 1921 Patented July 6, 1926.

UNITED STATES EDWIN LETTS OLIVER AND JOHN F.

*BORDEN, OF OAKLAND, CALIFORNIA.

FILTER.

Application filed November 5,1921. Serial No. 513,085.

This invention relates to a filter of the combined vacuum and pressure type and its. object is to produce a combined filter and settling tank which will be rapid and economical in operation.

A further object of the invention is to provide means whereby the cakesof filtered material produced upon the filter units will be discharged toward the center of the settling tank and more or less broken up before bein finally discharged therefrom.

A furt er object of the invention is to provide the settling tank with an overflow whereby whatever liquid may overflow can either be treated separately if it has settled sufiiciently, or can be returned to the filter tank for further treatment should that be required.

A further object of the invention is to provide an efiicient and economical means for shifting the vacuum from one filter unit to the other and for shifting the air pressure from one filter unit to the other whenever a sufliciently heavy cake has been produced upon any given filter unit.

Another object of the invention is to provide means wherebythe filter units will be given a sharp blast of air under pressure to relieve them throughout their length from the cake produced on the filtering media carried thereby, the filter units themselves being shaped with respect to their foraminous portions so as to supply a considerable volume of the filtrate to the foraminous surface whereby a reverse current is set u through the foraminous surface for'a su cient length of time to insure the complete removal from the foraminous surface of the cake roduced.

Ot er objects of the invention will appear as the description proceeds.

An embodiment of the invention is shown in the accompanying drawings in which the same reference numeral is applied to the same portion throughout, but we are aware that there may be modifications thereof.

Fig. 1 is a vertical sectional view throu h the length of the settling tank showing't e location of the filtering units therein.

Fig. 2 is a plan view of the complete apparatus.

Fig. 3 is valve.

Fig. 4 is a side elevation of the vacuum valve looking from the opposite side of Figure 3.

a side elevation of the vacuum Fig. 5 is a vertical sectional view of the vacuum valve.

. Fig. 5 is a side elevation of the vacuum valve looking from the inside, and

Flg. 6 is a transverse sectional view of a portion of the bottom of the settling tank.

The apparatus is mounted upon a long narrow tank 1 having a V-sha ed bottom as indicated in Figure 6 in wh1ch there is a shaft 2, said shaft being mounted in bearin s 3 to 6 inclusive, the latter of which is su ciently tight to prevent the loss of liquid through the same in order to permit the shaft 2 to extend through the end of the tank to receive the sprocket wheel 7.

The shaft 2 carries oppositely pitched screw conveyors or breakers 8 and 9, and it is rotated in such a direction as will push the cakes dropped off the filter units toward the center discharge pipe 10.- A plurality of prongs 11 are secured to the bottom of the tank near the center and the shaft carries a plurality of heaters 12 which serve to break up the particles of'sludge and prevent them from lodging in the tank bottom.

The filter units consist of a pin?" pipes 14. These pipes are perforated a portion of their length as lHdl nU-G at 15. and are then covered with any suitable filtering media as indicated at 16 over which wire or twine windings 17 are placed to hold the filtering media securely in place.

The filter tubes 14 have the pipes 18 to 21 inclusive connected therewith in sets of four and the set of four filtering tubes is supported in each instance by a cross bar for each set of eight tubes as indicated at 22. The pipes 18 to 21 inclusive in each instance connect with a header or manifold 23 from which a pipe 24 extends to the vacuum valve casing 25. As there are twelve sets of filter units there are twelve sets of the pipes 24, and there are twelve holes in the vacuum valve casing 25 to receive said pipes. I

The vacuum valve casing is supported by the two base flanges 26, 27, and it has a flange 28 for connection with the vacuum supply pipe. This valve is provided with an outer perlpheral chamber 29 which is con-.

'nected with an inner chamber 30 at inter-' vals between the passageways 31 in order toseries of pawl The'vacuum valve is supported by a stud shaft 36. This stud shaft 1s also connected with the air pressure pipe 37 at the back and having a nut 38 at the front bearrng upon the spiral spring 39, said spiral spring hold.- ing the packing land 40 in place against the valve hub. e valve has a passageway 41 and a chamber 42. The hub of the valve is cored out to receive: a packing material- 45 to hold said packat 44 a s irazl s rin P p g and a packing matemovement of the vacuum valve a different pipe 24 will receive the blow from the air pressure tank, and the filter and; that has just received the blow from the air pressure tank will anew receive the vacuum and accumulate a fresh cake of the material being collected thereon.

'At one side of the casing 25 there 15 a bearing 48 for a shaft 49. The shaft 49 carries a worm wheel 50 which is in mesh with a worm 51 on a'shaft 52. The shaft 52 is journaled in two bearings 53, 54 carried by the base flange of the vacuum valve -casing. The worm wheel 50 is also provided with a crank pin 55 which carries a pawl56, and the throw of the pawl is arranged to be such that the vacuum valve will be rotated one step on each revolution of the shaft 49. Under the worm 51 there is an oil receptacle 51'. I

The shaft 52 is also journaled in a bearing 58 at the end of the tank and it has a sprocket wheel 59 thereon around which the sprocket chain 60 passes to drive the conveyor shaft'2, power bein received by a suitable pulley 61 on the en of the shaft 52.

On the end of the shaft 49 opposite from the worm wheel 50 there is a cam 62, said cam-having .a notch 63 therein. Pivotally mounted on the vacuum valve casing base below the. cam 62 is an arm 64. ThlS arm has a roller 65 which bears upon the cam 62, and 1t is arranged to contact with the stem 65 of a valve 66 on the air pressure pipe 37, said pipe extending into the vacuum valve casing base and having the air pressure su ply pipe 68 connected to said base ontl ie opposite side therefrom to the connection for the pipe 37. A stiff spiral spring 69 is secured to the vacuum valve casin base flange 70 and passes through a ho e in the lower end of the arm 64, a nut 71 being provided for ad- 'justing the position of said spring upon said arm.

In order to supply the settling tank with material a launder 72 is provided at one I end thereof and overflow launders 73, 74, 75, 76 and discharge launder 77 are rovided around the sides of the settlin tan In operation the material is supplied to the tank through the launder 7 2 and a pres- I sure below atmospheric is applied to @the vacuum valve casing. This causes the filtrate to pass through the fabric ofv the several filtering units and to pass through the vacuum valve casing to a'suitable storage receptacle. At the same'time the shaft 52 is operated and the vacuum valve 34 is in termittently rotated.

The space in the cam 63 is arranged to be as long or short as may be convenient, and is arranged to open the valve 66 a short time after .the vacuum valve 34 has been moved from one position to another; thereupon the valve 66 is fully opened for a' short period which causes a portion of the filtrate which has accumulated within the several filtering units connected to the particular unit being blown, to be forced back through the filtering unit with sufiicient force to completely remove the cake formed on the outside of the same.

This object is attained because of theconsiderable quantity of filtrate contained in each filtering unit above the foraminous surface. As long as the filter is operated the filter valve is rotated to cause the cakes to be collected on and discharged from the several filtering units in rotation. As the material drops from -the several filtering units it falls to the bottom of the tank and is pushed by the conveyors toward the cen-' T ter of the tank; whereupon the breakers 11 and 12 break it up sufliciently to insure it passing through the discharge pipe 10 conveniently. At the same time the filtering operations are taking place, the liquid may beove'rflowing the edge of the tank and ma be either returned to this tank if not sufli ciently settled for further filtering, or re-' turned to a different tank for diflerent treatment. I

In the. present specification a vacuum valve has been referred to for efiecting the transfer of the filtrate from one side of the filter se tum to the other, but it will be understoo that the pressures used may be either above or below atmospheric as may be desired, the only requisite being a reversal of pressures on the filter se tum.

What we claim is as to owe, but various modifications may be made in the construction shown in the drawing and above particularly described form, within the purview of our invention:

1. An apparatus of the class described comprising a tank, a plurality of filtering units therein, a valve casing, pipes with open passages extendin from the tops of the several filtering units to the valve casing, a valve adapted to rotate over the openings in the valve casing to which the pipes are connected, said valve also having a chamber to be connected with one of said openings, means to deliver periodically to the latter chamber a blast of fluid to force the cake ofi the several filtering units in succession, and means to intermittently rotate the valve.

2. An apparatus of the class described comprising a tank having an overflow, a plurality of depending filter units in said tank having imperforate upper portions and foraminous lower portions, a conveyor to collect in one portion of the tank the cakes discharged from the filter sections, a valve casing having a plurality of openings therein, pipes extending from the several filtering units to said valve casing, a valve having achamber adapted to rotate over and cover several openlngs in the valve casing, said valve also having a chamber to cover only one of said openings, means to rotate the valve, means to intermittently supply said valve with fluid under pressure to clean the filter units successively, and means to discharge the collect ed pulp from the tank.

3. An apparatus of the class described comprising a tank, a lurality of depending filter units in said tan having top openings thereinto, each with an imperforate upper section, a conveyor to collect in one portion in the tank the cakes dischargin from the filter, a valve casing having a p urality of opemngs, pipes extending from the several fi tering units to said valve casing, a valve with openings adapted to pass over the o enings in said valve casing, means to Su p y one of said valve openings with flu1d under Eressureintermittently to force the cake 0 the filter units in succession, and means to rotate the valve and a discharge for the collected pulp.

4. An apparatus of the class described comprising a tank, alurality of depending filtering units, each aving an imperforate upper section therein means whereb cake formed on the filtering units Wlll be dropped into the tank, a screw conveyor to move the material to one portion of the tank,

a discharge conduit connected to the tank and b ers for came the material moved by the conve or to t e region of the discharge to be bro on up and mixed with the material in the tank to produce a substantially uniform discharge.

5. An apparatus of the class described the fr collect in one, portion of the tank the material dischar ed from the filtering units, breakers earned by the conveyor, and a discharge for removing the thickened pulp.

6. An apparatus of the class described comprising a plurality of filter units each filtering unitconsisting of a depending tubular member having its upper portion airtight and its lower portion foraminous, a filtering medium surrounding the lower portion of the filtering unit, means surrounding the filtering medium to preventit from being blown off the filter section and means to increase and diminish in rotation the pressures within the several tubes.

7. An apparatus of the class described comprising a tank having an overflow launder extending around the several sides thereof, a plurality of filter units therein, means to withdraw the fluid in the tank through the filter units in rotation collecting a cakethereon, means to reverse the flow of liquid through the filter unit to discharge the cake therefrom, a conveyor to collect the dischar ed cakes in one portion of the tank, breaker blades on the conveyor shaft, and a discharge below the breaker blades whereby a substantially uniform mixture is discharged. I

8. An apparatus of the class described comprising a tank, means to supply said tank with fluid to be filtered, a plurality of filter units therein, movable means for reversingthe flow of fluid through the filter' units whereby a cake is alternately collectedv upon and discharged from the several filtering units in succession, a conve or having breakers in the tank, and a disc arge adiacent the breakers 'whereby a substantia ly uniform pulp is removed from the tank.

9. An apparatus of the class described comprising a tank having an overflow launder adjacent its top, a plurality of filter units therein, movable means to reversethe flow of fluid throu h the filter units toalternately collect an discharge acake thereom, a conveyor having breaker blades, a

discha'r e adjacent the breaker blades whereby a su tantially uniform mixture is withdrawn from the tank and means to operate the filter units in rotation.

In testimony-whereof we have hereunto set our hands this 28th EDWIN LETTS. OLIVER.

JNO. F. BORDEN.-

day of October A. D. 

